促性腺激素释放激素类似物对化疗大鼠卵巢功能损害的干预作用

目的 探讨促性腺激素释放激素激动剂(GnRH-a)和拮抗剂(GnRH-ant)对环磷酰胺(CTX)诱导的大鼠卵巢功能损害的干预作用.方法 将72只雌性SD大鼠随机分为6组,即对照组腹腔注射生理盐水(NS)0.1 ml/d×11 d]、CTX组(第1天腹腔注射CTX 50 mg/kg,第2天起腹腔注射CTX 5 mg/d×10 d)、GnRH-a+NS组GnRH-a 0.375 mg 1次深部肌内注射(估计释放量为12.5μg/d,持续28～30 d),于用药第14天左右(连续5 d观察阴道涂片均处于动情间期)开始注射NS,用药方法同对照组]、GnRH-a+CTX组(同GnRH-a+NS组注射GnRH-a后,于用药第14天左右的动情间期开始注射CTX,用药方法同CTX组)、GnRH-ant+NS组GnRH-ant 0.3 mg皮下注射,以后每隔2天注射1次,共4次(估计释放量为100μg/d,共12 d),于第1次GnRH-ant皮下注射后第2天开始注射NS,用药方法同对照组]及GnRH-ant+CTX组(同GnRH-ant+NS组注射GnRH-ant后,于第1次GnRH-ant皮下注射后第2天开始注射CTX,用药方法同CTX组];每组12只.用药前后采用酶联免疫吸附法动态检测各组大鼠卵泡刺激素(FSH)、黄体生成素(LH)及雌二醇水平的变化,并于结束用药后的第1周内和第4～5周内(动情间期),各组分别处死6只大鼠,观察卵泡数量、卵巢重量的变化.结果 (1)血清内分泌激素水平:用药前后,对照组的血清LH、FSH、雌二醇水平无明显变化,CTX组的血清内分泌激素水平呈上升趋势.用药中,血清LH、FSH水平GnRH-a+CTX组为(42±8)、(124±45)μg/L,GnRH-a+NS组为(47±7)、(136±32)μg/L;GnRH-ant+CTX组为(31±5)、(178±54)μg/L,GnRH-ant+NS组为(36±7)、(198±27)μg/L;对照组为(118±16)、(350±35)μg/L;CTX组为(113±15)、(289±42)μg/L;分别比较,差异均具有统计学意义(P＜0.05).血清雌二醇水平GnRH-ant+CTX组为(3.98±0.74)ng/L,GnRH-ant+NS组为(3.58±0.43)ng/L,GnRH-a+CTX组为(1.46±0.22)ng/L,GnRH-a+NS组为(0.98±0.18)ng/L分别比较,差异均有统计学意义(P＜0.01).停药后,GnRH-a+CTX组、GnRH-a+NS组及GnRH-ant+NS组的血清LH、FSH、雌二醇水平逐渐接近对照组水平.但停药第4～5周时,GnRH-ant+CTX组LH、FSH水平(156±12)、(520±44)μg/L]与CTX组(178±18)、(546±36)μg/L]比较,差异无统计学意义(P＞0.05).(2)卵巢重量:停药第1周,GnRH-a+CTX组大鼠双侧卵巢重量为(18±8)mg/100 g,GnRH-a+NS组为(12±5)mg/100 g,均明显低于其他各组(30±9)～(37±8)mg/100 g],差异均有统计学意义(P＜0.05);停药第4～5周,GnRH-ant+CTX组大鼠双侧卵巢重量为(22±6)mg/100 g,CTX组为(20±4)mg/100 g,均明显低于其他各组,差异均有统计学意义(P＜0.05).(3)卵泡数量:停药第1周,GnRH-a+CTX组大鼠卵巢原始卵泡数为(689±39)个,GnRH-a+NS组为(824±45)个,明显高于GnRH-ant+CTX组(255±24)个]和CTX组(343±29)个];生长卵泡数GnRH-a+CTX组为(21±3)个,GnRH-a+NS组为(15±1)个,明显低于GnRH-ant+CTX组(110±21)个]和CTX组(87±17)个];分别比较,差异均有统计学意义(P＜0.05).停药第4～5周,GnRH-a+CTX组和GnRH-a+NS组的生长卵泡数(56±16)、(58±11)个]接近对照组水平(57±9)个];GnRH-ant+CTX组及CTX组的原始卵泡数和生长卵泡数均少于其他4组,差异均有统计学意义(P＜0.05).结论 GnRH-a对CTX诱导的大鼠卵巢功能损害具有保护作用,GnRH-ant对CTX诱导的大鼠卵巢功能损害没有明显的保护作用.

Effects of gonadotropin releasing hormone analogues on chemotherapy-induced ovarian function damage in rats

OBJECTIVE: To investigate the effects of gonadotropin releasing hormone agonist (GnRH-a) and antagonist (GnRH-ant) on cyclophosphamide (CTX)-induced ovarian damage in rats. METHODS: Seventy-two Sprague-Dawley female rats were divided randomly into six groups, which received normal saline (NS), CTX, GnRH-a + NS, GnRH-a + CTX, GnRH-ant + NS, and GnRH-ant + CTX respectively. Levels of serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E(2)) were measured successively by the enzyme-linked immunosorbent assay method, and half of the rats were killed in the first week and between the fourth and the fifth week after stop of medication, respectively to compare the weight of the ovaries and the number of the primordial follicles and the growth follicles. RESULTS: (1) Throughout experiment, the serum levels of FSH, LH and E(2) of the control group fluctuated slightly, while those in the CTX group kept rising. During medication treatment, compared with the control group (118 +/- 16) microg/L, (350 +/- 35) microg/L] and the CTX group (113 +/- 15) microg/L, (289 +/- 42) microg/L], the concentrations of LH (42 +/- 8) - (47 +/- 7) microg/L, (31 +/- 5) - (36 +/- 7) microg/L] and FSH (124 +/- 45) - (136 +/- 32) microg/L, (178 +/- 54) - (198 +/- 27) microg/L] in the GnRH-a groups and the GnRH-ant groups were maintained at low levels significantly and the levels of LH in the GnRH-ant groups were significantly lower than that in the GnRH-a groups, but the levels of FSH in the GnRH-ant groups were significantly higher than that in the GnRH-a groups (P < 0.05); and extremely different from the GnRH-a groups (0.98 +/- 0.18) - (1.46 +/- 0.22) ng/L], the level of E(2) of the GnRH-ant groups (3.58 +/- 0.43) - (3.98 +/- 0.74) ng/L] did not significantly decrease (P < 0.01). After stop of therapy, the concentrations of LH, FSH and E(2) in the GnRH-a groups and the GnRH-ant + NS group rose gradually and were similar to the levels of the control group (P > 0.05), but the levels of FSH, LH and E(2) of the GnRH-ant + CTX group rose obviously and were similar to the levels of the CTX group, especially the FSH , and the levels of LH and FSH of the GnRH-ant + CTX group (156 +/- 12) microg/L, (520 +/- 44) microg/L] and the CTX group (178 +/- 18) microg/L, (546 +/- 36) microg/L] were significantly higher than that of the other four groups (121 +/- 15) - (132 +/- 13) microg/L, (335 +/- 35) - (359 +/- 26) microg/L] at the 4(th) - 5(th) week after stop of treatment (P < 0.05). (2) At the 1(st) week after stopping therapy, the GnRH-a + NS group (12 +/- 5) mg/100 g]and the GnRH-a + CTX group (18 +/- 8) mg/100 g] had the lowest weight of ovaries which was significantly different from the other groups (30 +/- 9) - (37 +/- 8) mg/100 g, P < 0.05]. At the 4(th) - 5(th) week after stopping therapy, the GnRH-ant + CTX group (22 +/- 6) mg/100 g] and the CTX group (20 +/- 4) mg/100 g] had the lowest weight of ovaries which were significantly different from the other groups (29 +/- 5) - (31 +/- 9) mg/100 g, P < 0.05]. (3) At the 1(st) week after stopping therapy, there were the largest number of primordial follicles (824 +/- 45), (689 +/- 39)] and the lowest number of growth follicles (15 +/- 1), (21 +/- 3)] in the GnRH-a + NS group and the GnRH-a + CTX group, but there were the lowest number of primordial follicles (255 +/- 24), (343 +/- 29)] and the largest number of growth follicles (110 +/- 21), (87 +/- 17)] in the GnRH-ant + CTX group and the CTX group. At the 4(th) - 5(th) week after stopping therapy, the number of growth follicles in the GnRH-a + NS group (58 +/- 11) and the GnRH-a + CTX group (56 +/- 16) recovered to almost the level of the control group (57 +/- 9, P > 0.05), but the number of all kinds of follicles declined significantly in the GnRH-ant + CTX group (195 +/- 15), (36 +/- 12)] and the CTX group (212 +/- 11), (36 +/- 9)] compared to the other four groups (302 +/- 15) - (690 +/- 43), (44 +/- 12) - (58 +/- 11), P < 0.05]. CONCLUSION: In rat model, GnRH-a prevents the ovarian function damage induced by CTX, but GnRH-ant does not show similar protective effect.